Nissan Quest E52. Instruction — part 748

HAC-122

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

A/C ON SIGNAL

NO

>> Repair harness or connector.

3.

CHECK A/C ON SIGNAL CIRCUIT FOR SHORT

Check continuity between A/C auto amp. harness connector and ground.

Is the inspection result normal?

YES

>> Replace BCM. Refer to

BCS-98, "Removal and Installation"

.

NO

>> Repair harness or connector.

A/C auto amp.

—

Continuity

Connector

Terminal

M50

13

Ground

Not existed

BLOWER FAN ON SIGNAL

HAC-123

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

BLOWER FAN ON SIGNAL

Component Function Check

INFOID:0000000009652570

1.

CHECK BLOWER FAN ON SIGNAL

With CONSULT

1.

Turn ignition switch ON.

2.

Select “AIR CONDITIONER” of “BCM” using CONSULT.

3.

Select “FAN ON SIG” in “DATA MONITOR” mode.

4.

Check blower fan ON signal when the fan switch is operated.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Refer to

HAC-123, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009652571

1.

CHECK BLOWER FAN ON SIGNAL

1.

Turn ignition switch OFF.

2.

Disconnect A/C auto amp. harness connector.

3.

Turn ignition switch ON.

4.

Check output waveform between A/C auto amp. and ground with using oscilloscope.

Is the inspection result normal?

YES

>> Replace front A/C control (A/C auto amp.). Refer to

HAC-143, "Removal and Installation"

.

NO

>> GO TO 2.

2.

CHECK BLOWER FAN ON SIGNAL CIRCUIT FOR OPEN

1.

Turn ignition switch OFF.

2.

Disconnect BCM connector.

3.

Check continuity A/C auto amp. harness connector and BCM harness connector.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair harness or connector.

3.

CHECK BLOWER FAN ON SIGNAL CIRCUIT FOR SHORT

Monitor item

Condition

Status

FAN ON SIG

Fan switch

OFF position

Off

Except OFF position

On

+

−

Output waveform

A/C auto amp.

Connector

Terminal

M50

12

Ground

PKIB4960J

A/C auto amp.

BCM

Continuity

Connector

Terminal

Connector

Terminal

M50

12

M121

28

Existed

HAC-124

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

BLOWER FAN ON SIGNAL

Check continuity between A/C auto amp. harness connector and ground.

Is the inspection result normal?

YES

>> Replace BCM. Refer to

BCS-98, "Removal and Installation"

.

NO

>> Repair harness or connector.

A/C auto amp.

—

Continuity

Connector

Terminal

M50

12

Ground

Not existed

FRONT BLOWER MOTOR

HAC-125

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

FRONT BLOWER MOTOR

Diagnosis Procedure

INFOID:0000000009652572

1.

CHECK FUSE

1.

Turn ignition switch OFF.

2.

Check 15A fuse [No. 21 and 22, located in fuse block (J/B)].
NOTE:
Refer to

PG-80, "Fuse, Connector and Terminal Arrangement"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace the blown fuse after repairing the affected circuit if a fuse is blown.

2.

CHECK FRONT BLOWER MOTOR POWER SUPPLY

1.

Disconnect front blower motor connector.

2.

Turn ignition switch ON.

3.

Check voltage between front blower motor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 6.

3.

CHECK FRONT BLOWER MOTOR GROUND CIRCUIT FOR OPEN

1.

Turn ignition switch OFF.

2.

Check continuity between front blower motor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair harness or connector.

4.

CHECK FRONT BLOWER MOTOR CONTROL SIGNAL CIRCUIT FOR OPEN

1.

Disconnect A/C auto amp. connector.

2.

Check continuity between front blower motor harness connector and A/C auto amp. harness connector.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair harness or connector.

5.

CHECK FRONT BLOWER MOTOR CONTROL SIGNAL

1.

Reconnect front blower motor connector and A/C auto amp. connector.

2.

Turn ignition switch ON.

3.

Operate MODE switch (front A/C control) to set air outlet of front air conditioning to VENT.

4.

Change front fan speed from Lo to Hi, and check duty ratios between front blower motor harness connec-
tor and ground by using an oscilloscope.

+

−

Voltage

Front blower motor

Connector

Terminal

M140

3

Ground

11 – 14 V

Front blower motor

—

Continuity

Connector

Terminal

M140

1

Ground

Existed

Front blower motor

A/C auto amp.

Continuity

Connector

Terminal

Connector

Terminal

M140

2

M50

10

Existed